Surveyor&#39;s level.



G. N. SAEGMULLER.

SURVEYOB.S LEVEL. APPLIGATIO FILED FEB. 27, 1911. 1,1 1 5,026. Patented oct. 27, 1914.

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SURVEYORS LEVEL.

APPLICATION FILED r I:B 27,1911.

Patented Oct. 27, 1914.

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GEORGE N. SAEGMULLER, 0F ROCHESTER, NEW YORK, ASSIGNDB T0 BA'USCH & LOMB OPTICAL COMPANY, 0F ROCHESTER, NEW YDBLK, A CDRPGRATQN 0F NEW 'YQRR sunvnxoas LEVEL,

Specieation of Letters latent.

Patented 0ct. 27, 1914.

To all whom t may concern:

Be it known that I, Gnocca N. Sanc.- MULLnn, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements 1n Surveyors Levels; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of the specification, andto the reference-numerals marked thereon.

My present invention relates to optical 1nstruments and particularly to instruments for determining levels 'and known generally as surveyors leveling instruments, and as such it has for its object to provide an improved form of telescope whereby observation may be made through either end of the instrument to obtain views by looking in opposite directions, thus greatly facilitating the labor of the? surveyor in setting up the instrument at each station, and to test the adjustment.

My invention has for its further object to provide a novel mounting for the telescope whereby it may .be rotated end for end through an accurate arc of 180 and locked on its vertical axis in each position of adjustment to the end that the o erator may quickly Aadjust the verticality o said axis.

Another object of the invention -is to provide a means for tilting the axis of .the telescope relatively to the vertical axis of the instrument to obtain a finer or more delicate adjustment in a shorter space of vtime than can be gotten by the usual leveling screws of the base.

A further object of my invention is to provide a mounting for the cross-hairs of the telescope whereby these may be shifted laterally in all directions to position them in the true optical axis of the coperating lens system;

To these and other ends the invention consists in certain improvements and combinations of parts, all as will be hereinafter more fully described7 the novel features bei-ng pointed out in the claims atI the end of the specification.

In the drawings: Figure 1 is a vertical sectional view of a surveying instrument .or

level illustrating the present embodiment of my invention; Fig. 2 is an end View taken on the line 2*- X of Fig. 1; Fig. 3 is a horizontal view taken on the line 3*-3x of Fig. l; Fig. 4 .is a detail View showing the crosshair mounting in elevation and taken on the section line lx-4* of Fig. 1, and Fig. 5 is an enlarged sectional view taken through one edge of the cross-hair adjusting rings.

Similar reference numerals in the several figures indicate similar parts.

In carrying out my present invention I have sought to produce a surveying instrument adapted to be used for precise leveling operations which will possess certain 'advantages both from a manufacturing and operating standpoint. In the use of level ing instruments it is absolutely necessary that the surveyor be particularly careful in adjusting the instrument so that when rotated on its vertical axis the optical axis of the telfwcope will rotate in a horizontal plane. In the ordinary Y level it is, of course, pre-supposed that the vertical axis of the instrument on which it rotates occupies a true angular position of 90 relatively to the horizontal optical axis of the telescope, and that the bubble tube on the telesco is accurately positioned in reference to the line of collimation of the telescope when the instrument leaves the makers hands. Such being the fact the surveyor then is merely obliged t0 adjust the instrument to determine the verticality of its vertical axis each time the instrument is erected at a new station. However, in order that he may' check his work and be certain that it is absolutely accurate, within certain reasonable variations permitted according to the nature of the survey, it is also necessary for him to verify the adjustment of the different parts of his instrument at least once or twice during each days work.

My invention as applied to levels, has for its object the simplifying of operations necessar to check the accuracy of adjustment o the bubble tube relatively to the line of collimation, to avoid the necessity of removal of the telescope from and its reversal in the Ys, as is customary in the usual type of Y levels, and also to facilitate the rapid adjustment of the vertical axis of the instrument at the various stations when it is set up.

An instrument embodying my present invention will be mounted upon the usual tripod or other suitable support to which it is connected by the adjustable leveling head, the one in the present instance being that illustrated in Patent No. 955,911, granted the latter being provided with the bubbleV tube 14. rlhe base 7 is rigidly connected to. the vertical axis and instead of forming the;` support for the Ys these are mounted, as shown, on the tilting member 8, which is; capable of rocking slightly in a verticali plane, it being connected in the present in` stance with the base 7 by means of a hori-f zontal pivot l5 lying lin the plane of the ver-I tical axis 2 and forming a hinge connection between the ends of the lugs or posts 16 and 17. The base 7 is provided along its lateral' edges with upwardly extending flanges 184 and at each end with similar flanges 19, which parts are inclosed by the depending side walls 20 on the member 8.a Near one.v

end of the base is an operating member in the form of a cam 25 journaled on a horlzontal axis 26 journaled at its ends in up.

wardly extending flanges 27 on the base 7. (loperating with the cam is a small wear piece 28 projecting downwardly from the underside of the tilting member 8 to which it is attached by screws 29. 1n order 4to simplify the construction and the means em-` ployed for operating the cam, the latter 1 s formed centrally in a spiral pmion 30, as best portrayed in Fig. 2, with which coperates a worm 31- attached to the operating shaft 32 journaled in the Harige 19 at each end of the base, the extremities of the shaft projecting through slots 33 in the end walls of the member 8 andprovided with the operating finger-pieces or knurled kno-bs` 34 and 35 by means of which the shaft may be conveniently rotated. The member 8 is counterbalanced on its pivot 15 and supported for yielding adjustment relatively to the base 7 by means of a 'plurality of springs, such as 36, each of'which surrounds a post 37. 0n the end of each of these posts is a head 38 bearing against one end of the spring inclosed within a tubular sleeve 39, the lower end or which engages the other'end of the spring. rllhe base 7 also carries a spirit level 40 arranged at one side of the vertical axis of the instrument and beneath an aperture provided in the tilting member 8, this level being provided for the assistance of the surveyor in setting up his instrument in the first instance, by means of which he can roughly determine the approximate verticality of the axis 2, the liner adjustments which are subsequently required being determined by the position assumed by the bubble in the tube 14 as it is rotated successively into one position or another relatively to the leveling screws 3, 4 and 5.

The arrangement of the optical parts of the telescope, which will be more fully described hereinafter, permit the rotation of the instrument upon its vertical axis and the reading of the divisions of the stadia rods which are set up in a straight line with the instrument and at opposite sides thereof, when it is desired to test the accuracy of the instrument. Unlike other leveling instrumentsthe telescope is equipped with an arrangement of lenses whereby readings may be taken by sighting alternately through opposite ends ofthe telescope. This of rcourse necessitates a reversal of the position of the telescope of 180 on its vertical axis and a corresponding shifting of the bubble tube, this changing of the telescope end for end and reversal of the bubble tube being equivalent to the usual operation of removing the telescope from the Ys and replacing it in reversed position therein, but possesses the advantage of obviating the inconvenience and diiiculty to which this operation subjects the surveyor.

In an instrument embodyino` my invention the removal of the telescope from the Ys is unnecessary, and therefore to provide a means for quickly rotating it accurately through an arc subtended by an angle of 180, either when double sighting the telescope in one direction, or when sighting it in opposite directions, ll provide means for locking it initially in its adjusted position, which may be released and subsequently engaged when the telescope has been revolved. 'llhe locking device in the present instance comprises a small latch member 41 arranged stationary relatively to the base 7 having a handle portion 41a and adapted to be swung into and out of a slot formed between the depending ears 42 at one end of thebase when the latter is rotated `to subsequently engage between similar ears 43 at its opposite extremity, the latter beinpreferably provided with set screws 44 w ich may be adjusted to compensate for any inaccuracy in mechanical construction of the parts which may besuicient to throw the line of sight of the instrument slightly to one side or the other oit an absolutely 'straight line,

numana when the base is revolved upon the vertical axis.

The locking device is always stationary relatively to the base 7 when the instrument is used in sighting upon a distantl object, but as the angular position of the instrument relatively to its su port-is not determined until the levelin a j ustrnents have been 'pferformed, said 1 ing device is pivoted upon an arm 45, rotatable about the vertical axis 2, being supported upon an independent bearing in the form of a sleeve 46 mounted on the leveling head y1 to which it may be rigidl secured. Underlying the arm 15 is a similar arm 47 provided with a clamping screw 48 coperating with the sleeve 46 and having at its outer end lugs 49 and 50 carrying the tangent screw 51 bearing against one side of the arm 45 and the opposing springoperated plunger 52 engaging the opposite side of the arm to yieldingly hold it 1n engagement with the tangent screw.

The telescope 13 Icomprises the usual tube, as shown, held at its ends in the pivot rings 11 and 12 which are split as shown in Fig. 2,

the upper and lower parts of said rings being clamped' together by screws 53, whereby the tube is rigidly held instead of being rel movable as is customary in instruments of this character. It will' also be noticed that the Ys 9 and 10 instead of being adjustable are rigidly fixed on the tilting member 8.

The bubble tube 14 is mounted in a casing 54: the extremities of which are provided with lugs 55 and 5G secured between adjusting nuts on the threaded ends of the supporting columns 57 and 58,l which latter are rigidly mounted on the telescope tube 13. Employed in connection with the bubble tube is a reflectorlor mirror 59 supported in a yoke 60 whereby it may be inclined in two different-angular positions, as shown in full and dotted lines in Fig. 1, to permit 'the operator to view the position of the bubble in its run-way irrespective of which of the two ends of the telescope may be used as the eye-piece end.

In the arrangement ofthe optical elements of the telescope I provide at each end therel of similar sets of objective lenses A and B and between the lenses, in the field of the` n nage formed by either of them when used singl I provide the usual set of cross-hairs, whic in the present instance, occu y the and i B. With these similar lenses Iemplcy an positions indicated respectively by ocular at the end of the telesco e tube in ing lens of proper curvature, a though it preferably comprises a system of lenses for also erecting an image. In usev I locate the ocular at the end of 'the telescope tube in such close proximity to one of the objectives l that the optical pr erties thereof have'no effect upon the ocu ar, the-sight obtained through the latter being the same in all respects as if looking through a clear lass. The ocular when so arranged in rear o and in proximity to one lens will coperate with the distant objective lens at `the opposite end of the telescope tube and form an optical combination therewith to invert and magnify the image displayed at its respective set of cross-hairs. The ocular might be supported independently of the telescope tube, but in practice the construction is simplified by the provision of means for detachabl mounting it thereon whereby it may be easi y disengaged, the instrument rotated, and the ocular again secured in position on the opposite end of the tube. This is conveniently accomplished by providing the mountings a and b, in which the respective objective lenses are held, with collars a and b into which the mounting c of the ocular is accurately fitted, said collars being provided with projections a2, b2 in the form of segmental threads with which similar projections c2 on the ocular mounting c coperate. This arrangement of parts it will be observed merely requires that the ocular be given a partial rotation to either connect or disconnect it in position at either end of the telescope. i It is possible, but not practicable to so position the objective lenses A and B and their respective sets of crosshairs, and to so construct the ocular that it will accurately focus upon the cross-hairs in respect to both objectives when sighting upon objects at different distances fromthe instrument, but as there are many factors which it is necessary to take into consideration in building the instrument and grinding the various lenses` to obviate any parallax, I dispose centrally in the telescope a longitudinally adjustable double concaved lens D which may beadjusted relatively to objective lenses to properly focus their images. This lens is preferably mounted in a ring d secured in a tube A130 provided at each end with exterior rings 131 which are guided cn the ribs 132 extending longitudinally of the vtube 13. The adjustment of the `tube 130 is obtained by means of the rack 133 engaging the inion 134 mounted on the shaft 135 provi ed at each end with the knobs 136, two knobs be ing employed so that one of them always occupies a position at the right hand side of the instrument for the convenience of the operator.

In the form of telescope described where two sets of cross-hairs are employed, it is desirable that the vertical and horizontal crosshairs `should 'be so ldisposed relatively to each other that their points of intersection may be accurately disposed in the line of collimation 'or true axes of the lenses. In other words the corresponding cross-hairs of each set should accurately lie in the horizontal and vertical planes intersecting the vertical axis of the telescope.

Ordinarily the reticule ring on which the cross-hairs are mounted is adjustable side- Wis'e well as in an upward and downward direction by means of capstan screws, the cross-hairs being properly positioned relatively to the horizon by either rotating the ring in the screws or rotating the telescope tube in the pivot rings. In my present'invention I have provided an impro-ved reticule adjusting mechanism which entirely obviates the use of capstan screws, and in carrying out this feature of the invent-ion I provide for each set of cross-hairs a cylindrical section or barrel, forming part of the telescope tube, in which the cross-hair adjusting devices arey mounted. This barrel :Eo-rms a component element of the tele- 1 scope tube and in the illustrations is shown as comprising the ring 65, carrying the mountings a or 5 of the objective lenses, having the interior threaded portion 66, by means of which it is secured to the annulus 67 on the tube 13. Contained within the barrel are three rings 68, 69 and 70 itted one within the other, the last mentioned or outermost ringbeing accurately fitted and journaled within the barrel and supporting the other two rings. The outer ring 70 also rests against the inner shoulder 71 of the barrel, which is spaced inwardly a short distance from the inner surface of the objective lens, this distance, however, being regulated by the amount of separation desired between said lenses and the cross-hairs carried on the innermost ring 68, which are preferably secured to the outer edge of the latter. The inner surface of the ring 70 is eccentric to its outer surface and the same is true of the intermediate ring 69, while the outer and inner surfaces of the innermost ring 69 are concentric. rlhe rings 69 and 68 are also provided with annular shoulders as shown in Fig. 1, that of the former lying against the inner edge of the ring 70, while lthe shoulder on the ring 68 similarly engages the inner edge of the ring 69. rIhese shoulders as Well as the ring 70, are provided in their peripheries with apertures adapted to receive the pointed end' of an adjusting pin which may be employed for rotating said rings, and to permit the operation of the pin a portion of the wall of the barrel is removed, as indicated at 72, it being normally covered by a cap ring 73 threaded under the exterior of the barrel.

The several rings are frictionally held in the barrel by means of a ring nut 74, which engages the washer 7 5 lying against the inner edge of the ring 68, the adjustment of the nut serving to hold the several rings one Within the other and to compress them against the shoulder 71with sufticient friction to prevent their accidental displacement. The arrangement of these adjusting devices it will be understood is duplicated at each end of the telesco-pe. When it is desired to adjust the separate sets of crosshairs so that they assume true horizontal and vertical directions, this is conveniently done by rotating the innermost ring or reticule 68, it being unnecessary to move the telescope in the bearing rings 11 and 12. Subsequent adjustments which may be necessary to position' the cross-hairs laterally to bring their points of intersection into the line of collimation of the telescope is accomv plished by rotating either the intermediate eccentric ring 69 or the outer eccentric ring 70, or by rotating both of these relatively to each other, their various degrees of eccentricity permitting the accomplishment of the object sought.

An optical instrument constructed in accordance with my invention being reversible greatly simplities the adjustments necessary in truing up the instrument when the parts are first assembled, and lessens the work of the suryeyor in determining the accuracy of their adjustment, and also facilitates the adjustment of the instrument as a whole each time it is set up at a new station or point of observatio-n.

I claim as my invention:

1. In an optical instrument, the combination with a tube, similar objective lenses at opposite ends of the tube and an ocular adapted 'to be placed at either end of the tube, and when so placed at one end of the tube to form an optical combination With the objective lens at the other end of the tube, of two sets of cross-hairs arranged inI the tube, a revoluble and independently adjustable mounting for each set of crosshairs journaled in the tube for positioning both sets of cross-hairs in like positions vertically land horizontally in the tube, said mountings also comprising means for further adjusting the cross-hairs with their respective points of intersection in the line of collimation of the instrument.

2. In a leveling instrument, the combination with a telescope provided with two object-ive lenses at its opposite ends and an ocular applicable to either end of the telescope, of a horizontally revoluble base supporting said telescope and a relatively stationary locking device adapted to cooperate with the base at points located at opposite sides of the axis of rotation to first secure the telescope in initial position with the ocular and one objective forming an optical combination and pointing in one direction, and secondly to secure it when rotated to point said optical combination of lenses in the opposite direction.

3. In an optical instrument, the combinaing said sets relatively to each other and to tion with a tube mounted for horizontal the line of collimation of the lenses. observation in o osite directions and, ro- 1 vided with two Islmilar Vobjective lensels) :itl GEORGE N' SAEGMULLER' 5 its opposite ends and an ooular coperatng Witnesses:

with both objectives, of two sets of cross VVLILLIAM G. WooDWonTH, hairs and means for independently adjust- DANIEL M. SMITH. 

